Metal recovery device



June 30, 1970 cs. A. CENKNER METAL RECOVERY DEVICE Filedfneo. 21, 1967 -2 Sheets-Sheet l 4 m a a 2 f v M7 lla. H O a 6 L 6 2 70 2 0/ 2 6 4 2 4 \\\\\M\ Z//n tu .|\|\P 1 4 .c G. 6 J m I .u 6 I f s M 4 2 M 2 M 2V v L M/ 1. M/ a V.\ n m l I l a a 4 o a o 63.@ a/ Je /m/ 6.J \.J 2 n n l *UW 4'/ J 3 v 6 .O/ L 4/ m 2 2 L w INVENTOR 650,66; A @IFA/naf ATTORNEYS June 30, 1970 c;t A. cL-:NKNER METAL RECOVERY DEVICE 2 Sheets-Sheet 2 Filed Dec. v21, 1967 V lNveNToR faeGf A. Cf/vA//vf BYv @, ya@ ATTORNEYS United States Patent O 3,517,918 METAL RECOVERY DEVICE George A. Cenkner, 18470 George Washington Drive, Southield, Mich. 48075 Filed Dec. 21, 1967, Ser. No. 692,493 Int. Cl. B01d 17/02 U.S. Cl. 266-37 8 Claims ABSTRACT F THE DISCLOSURE An apparatus for separating molten non-ferrous metals and/or alloys, such as zinc, aluminum,et c., from hot dross which has been skimmed from the surface of molten baths, which apparatus includes an essentially V-shaped container into which the hot dross is introduced directly from the surface of a melt in a refining furnace or the like. The bottom of the bin or container is disposed at a slight angle to horizontal, and at the lower end thereof exhibits an outlet provided with a quick-clamp closure member, permitting easy manipulation for withdrawing the molten metal from the device. A reciprocable blade suspended within the bin is drivenpthrough the dross to impart vertical and laterallmovement to the dross and thereby cause the pure metal to separate from the ashes and gravitate toward the lbottom of the bin.

A primary object of my invention is to provide an improved and eicient 4device of the character above indicated for remo-ving metal from a dross which has been skimmed or raked from a melt in a refining furnace.

Another object is the provision of such a device including a generally V-shaped bin or container, the converging side walls of which are constructed as separate parts releasably coupled together, whereby one side wall may be swung away from the other to unload the dross quickly and conveniently once the metal has lbeen reclaimed therefrom.

A further object is to provide a `device of this character including a reciprocable blade positioned within the V- shaped bin and shaped to impart both upward and lateral movement to the ashes and permit the molten metal to drain through to the bottom of the container.-

Other objects, advantages, and meritorious features will more fully appear from the following description, claims and accompanying drawings, wherein:

FIG. 1 is a side elevational view of a metal recovering device embodying my invention;

FIG. 2 is a top elevational view of the device shown' in FIG. 1;

FIG. 3 is an enlarged cross sectional view taken through the Ibin or container of FIGS. 1 and '2 showing the bin construction and the mounting of a reciprocable blade within the bin;

FIG. 4 is a side elevational view of the reciprocable blade shown in end elevation in FIG. 3; and

FIG. 5 is a partial perspective view of one end of the bin showing the molten metal outlet and the means for opening and closing the outlet.

Referring now more particularly to the drawings, a metal recovery device embodying my invention is indicated generally by the numeral 20 therein. The device is preferably supported on a frame or the like which includes a plurality of upright support members 22 and horizontal support members 24 which may be welded or bolted together to provide a rigid supporting structure for the device 20. Suitably supported on a small platform or the like 26 adjacent one end of the supporting structure is an electric motor 28 the function of Iwhich will be described hereinafter. As shown in FIG. 1, the upper support members of the frame 24 are inclined at a slight rice angle to the horizontal and it is upon these members that the device embodying my invention is suspended, the recovery device itself shown at 20 being spaced above the floor for more efficient operation.

The device embodying the invention comprises a generally V-shaped bin as shown in cross section in FIG. 3, the side walls of the bin shown at 30 and 32 respectively converging at their lower ends and being supported at their upper ends on the frame members 24. The bin is closed at its opposite ends by end walls, one of which is shown at 34 in FIG. 5. The bin is supported on the frame members so that the lower end of the bin is inclined with the horizontal, as shown in FIG. 1, and it has been found that an angle of seven degrees has been eiective to produce the desired result.

As can be seen from FIG. 3, one of the bin side walls 30 is substantially planar, being secured as by welding at its upper end to frame member `24 and having a free lower end portion. The opposite converging side wall 32 is hingedly connected at its upper end to the frame members as by a hinge 36 Iwelded to the upper marginal edge of the side wall, while the lower edge portion of wall 32 terminates in a generally horizontal extending 'portion 38 which forms a at bottom for the bin and overlies the lower marginal edge of the opposite side wall 30. 'Secured to the outer surface of side wall 30 adjacent the lower end thereof is a bracket or the like 40 from which depends one element of a clamping device 42, the other portion of the clamping device 42 being secured to the bottom wall portion 38. The clamping device 42 is a quick disconnect clamp which may be released to permit the side wall 32 to swing on its hinge 36 from the position shown in solid outline in FIG. 3 to the dotted outline position shown therein. Clamps such as the one shown at 42 are readily commercially available, and the exact structure of the clamp therefore need not be described in detail. Preferably it includes a handle portion 44 projecting therefrom which may be manually operated to release side wall 32 for its swingable movement away from side wall 30.

Extending across the bin and spaced thereabove are a pair of supporting shafts 46 and 48, each of which are supported at opposite ends in V-groove roller bearings 50. A vertical plate 52 extends between the shafts 46 and 48 and is secured thereto so as to extend into the bin substantially centrally of the side walls 30 and 32 Secured to the lower end of the plate 52 as by bolts 54 or the like is a center blade 56 which terminates at its lower edge spaced slightly above the bottom wall 38 of the bin. A pair of generally trapezoidally shaped blade mmebers 58 and 60 are secured to the center blade 56 adjacent its lower edge as by welding, the longer base of the trapezoid blade members being lowermost, and being spaced slightly above the bottom wall portion of the bin, as shown most clearly in FIG. 4. The members 58 and 60 are secured to the center blade 56 adjacent its forward edge, and an identical set of blade members are secured to the center blade adjacent its rearward edge, one of which blades is shown in FIG. 4 at 601. There are thus provided four trapezoidally shaped blade members secured to the center blade 56 adjacent its lower end, the purpose of which will be apparent as the description proceeds.

In order to provide for reciprocable movement of the blade 56 and its attached members back and forth within the bin, the roller bearings 50 are each supported on a track 62 which is of inverted V-shape in cross section, as shown in FIG. 3. Suspended above the rollers 50y are guides 64 which are generally V-shaped in cross section, and these guides are positioned in close proximity to the rollers 50 to prevent the latter from leaving the track 62 during their reciprocable movement. As can be seen from the drawings, the track 62 and guides 64 are disposed at the same angle as the bin, so that movement of the blade assembly back and forth within the bin will be such as to maintain the lower edge of the blade portions S8 and 60 at a constant distance from the bottom wall 38 of the bin. If so desired, covers made out of sheet metal or the like may be utilized to enclose the members 50, 62, and 64, such as is .shown at `66 and 68 in FIG. 5 to prevent entry of foreign matter into the moving parts and insure against injury to personnel during operation of the equipment.

Suitably positioned on a platform 70' located substantially above motor 28 and to the rear of the bin, are a pair of spaced apart bearing blocks 72 and 74 between which Aextends a shaft 76 carrying a sprocket 78. The shaft of motor 28 is correspondingly provided with a sprocket 80 and a chain 82 entrained over the sprockets 78 and 80 establishes a drive therebetween. Secured to shaft 76 adjacent opposite ends thereof are a pair of crank arms 84 and 86, the outer ends of the cranks being pivotally connected to a pair of links 88 and 90 respectively. The opposite ends of the links 88 and 90 are journalled onto shaft 46, as most clearly shown in FIGS. 1 and 2.. As can be seen from an examination of FIG. 1, the rotation of sprocket 78 by its drive connection with motor 28 rotates crank arms 84 and 86 about shaft 76, and turn oscillating arms 88 and 90 to produce reciprocable movement of the shafts and roller assembly along the track 62. As the center blade 56 and its depending blade portions move with the shafts and rollers, the above mentioned movement produces reciprocation of the blade back and forth within the bin, thereby producing the desired agitation of the material within the bin, as more fully described hereinbelow.

At the lowermost end of the bin, that is at the forward end of bottom wall 38 an outlet for the molten metal is provided, such being shown in FIG. at 92 as being a cutout in the lower marginal edge of forward end wall 34. Closure of the outlet opening is affected by a toggle assembly secured to the end wall 34 by a bracket 94, the toggle assembly including a closure plate 96 mounted on an arm 98 pivotally secured to the bracket, and a toggle handle 100, swingable movement of the handle operating to shift the plate 96 into and out of engagement with the outlet opening 92. With the described assembly, the outlet opening 92 may be quickly and conveniently opened and closed merely by manual movement of the projecting handle 100. This outlet closure assembly is also shown in FIG. 1. In FIG. 5, the side wall 32 is shown in its swung-away or open position, disposing bottom wall portion 38 thereof in its position shown at 381 in dotted outline in FIG. 3. As can be seen from FIG. 5, the bottom wall portion 38 may be provided with a chute or the like 102 welded to the end of bottom wall 38, the chute serving to convey the molten metal issuing from the outlet 92 away from the outlet.

In the operation of the device embodying my invention, a charge of hot dross is skimmed or raked from the surface of a melt in a refining furnace and transferred directly to the bin of the invention, the bin being closed, as shown in solid outline in FIG. 3. Upon introducing the hot dross into the bin, the motor 28 is started, driving sprocket 78 through chain 82 to rotate shaft 76. The cranks 84 and 86 being secured to the shaft 76 rotate therewith, and such rotation serves to oscillate arms 88 and 90 in a conventional fashion, drawing the blade assembly on rollers 50 back and forth on the track 62. Any tendency of the rollers 50 to leave the track 62 is obviated by the provision of the guide rail 64 which is positioned to insure contact between the rollers and the track. The center blade 56 and the component blades 58, 60, 581, and 601 are thus moved back and forth within the charge of dross in the bin, in a path that is substantially parallel to the bottom wall 38 of the bin.

The inclined faces on the trapezoidally shaped blade components such as shown at in FIG. 4 tend to move the dross up from the bottom wall 38 as the blade is shifted therethrough, while the center blade S6 serves to cut through the dross and -move it laterally with respect to the bottom wall 38. Thus rather than shaking or agitating the dross within the bin, the shape and movement of the blade portions tend to move the dross vertically and laterally to allow the molten droplets of metal suspended in the dross to gravitate to the bottom of the bin. The blade portions are specifically engineered to sift and separate the dross and allow the molten metal to be separated and accumulate at the bottom wall 38- rather than to beat and agitate the dross, as was the case with certain of the prior art devices which have been proposed. The V-shaped bin likewise contributes to causing the material therein to gravitate down the side walls 32 and 34 toward the bottom of the bin 38 for more efficient action of the blade portions.

In order to maintain the dross in liquid condition throughout the operation of the device and keep it from solidifying in the bin, there may be provided a burner, preferably in the form of a line burner extending below the bottom wall 38 and spaced slightly therebelow to heat the bottom wall and prevent the molten metal from solidifying. My device may also be provided with an air operated vibrator attachment shown in FIG. 1 at 104 to vibrate the bin and keep the material therein moving thus assisting in the action of separating the molten metal from the heat dross. After a sufficient time period has elapsed with the motor 28 and vibrator 104 operating, the outlet 92 is opened by releasing the toggle through movement of the handle 100 and permitting the molten metal to drain from the outlet 92 down the chute 102 and into an ingot mold for re-use. The device is allowed to continue operating, and the molten metal is released by opening the outlet 92 until all of the recoverable molten metal has been released from the bin.

Once the molten metal has been exhausted from the bin, operation of the device is interrupted and the wall 32 is swung on its hinge 36 downwardly and away from the opposite wa'll 30 by releasing the toggle clamp` 42, the hinged wall shifting to its position shown in dotted outline in FIG. 3. In this position, the ashes remaining in the bin are free to drop downwardly out of the bin into a suitable. container placed therebelow, so that the bin may be charged with a fresh batch of dross. As the ashes remaining in the bin may solidify, when the bin is opened by releasing toggle 44 the vibrator 104 is preferably restarted to agitate the bin and cause the ashes to drop therefrom. In addition, the motor 28 may be operated during this period to actuate the blade 56 in its back and forth movement within the bin to cut through and dislodge any of the remaining ashes that are stuck in the bin. Once the bin has been completely emptied, the side wall is again swung in position and the toggle locked by manipulation of handle 44 to ready the bin for a fresh charge of dross.

I have found that by employing the device embodying my invention, the recovery of the molten metal suchas zinc from hot ashes may be accomplished with the minimum amount of time. These ashes are formed when the zinc dross on top of the liquid zinc in the melting furnace is covered with flux and raked. The dross becomes exothermic, and during this reaction approximately of the molten Zinc drains through the hot ashes into the liquid zinc bath. The ashes remaining on the top of the melt are then skimmed off and ordinarily discarded as waste scrap. However, so-me of the molten metal is present in the dross that is raked 0r skimmed from the top of the bath or melt, and by utilizing my device, this valuable metal may be recovered from the dross. I have found that under normal conditions my device will remove approximately of the molten metal which is skimmed olf the melt and remains in the hot ashes. Of

course, the free metal content of the dross will vary considerably depending upon the melting conditions in the furnace, the flux employed, and the composition of the alloy in the melt. In addition, the skill of the operator and the care used in skimming or raking the dross from the melt in the furnace has a pronounced effect on the amount of metal which is taken off with the dross. It has been found that ordinarily it is not feasible from an economic standpoint to process dross which contains less than about 30% by weight of free metal. Conversely, there is no limit on the maximum amount of freetmetal that may be present in the dross in order that the recovery operation may be successfully carried out. It has a'lso been foundvthat a higher percentage recovery of pure metal is obtained from drosses which contain 80% or more of the free metal. i

The metal reclaimed from dross by my process is singularly free from oxides and non-metallic inclusions and therefore it .can be returned to the melting furnace without contaminating the melt. An additional advantageous feature of my device is that it can be mountedon a platform disposing the outlet opening or tap hole above the remelt furnace, so that upon opening of the tap, the free metal obtained will drain directly back into the furnace without the necessity of further handling.`

What is claimed is:

1. An apparatus for recovering molten metal from hot dross skimrnings, comprising: a dross receptacle" having side walls converging at their lower ends to define a generally V-shaped cross section, a vertical blade sup-I ported for reciprocal movement within said receptacle generally parallel to the vertical axis centrally located between said side walls, said blade having a base portion generally parallel to the base of said receptacle and adjacent thereto, said blade including forward and rearward end blade portions inclined upwardly from the ends toward said vertical axis and facing perpendicular to said axis to impart an upward motion to the dross as the blade is reciprocated in said axis, and a power source coupled with said blade for driving the blade.

Z. The' apparatus defined in claim 1, characterized in that said blade portions are in the form of truncated triangles with the -base generally parallel to the base of said receptacle.

3. The apparatus defined in claim 2, characterized in that the base of said blade is supported adjacent the base of said receptacle. y

4. The apparatus defined in claim 1, characterized in that said apparatus includes a plurality of blade portions suplported generally in the vertical axis of said receptac e.

5. The apparatus defined in claim 4, characterized in that said blade portions-fhave a common axis generally parallel to the base of said receptacle.

6. The apparatus defined in claim 1, characterized in that one of the walls of said receptacle defining the V- shaped cross section ishinged adjacent-,the top of the receptacle to permit the receptacle to be opened at the base to permit removal of the dross.

7. The apparatus defined in claim 1, v,characterized in that: the -base of said receptacle is inclined at a slight angle to the horizontal, such that the molten metal in the receptacle migrates ltoward the lowest end as the dross is lifted by the blade.y portions.

8. The apparatus defined in claim 7, characterized in that the base of said receptacle is inclined at an angle of seven degrees to the horizontal.

References Cited UNITED STATES PATENTS 9/ 1932 Downes et al. 210-527 7/ 1933 Schmeller.

U.S. Cl. X.R. 210-527 

